Z-axis zero from the pipe surface (sheetcam rotary+Mach3)

[yurapak]

I work with sheetcam rotary and mach3, we use a postprocessor PlasmaRotary Mach3.scpost.
The Z axis is measured from the centerline of the pipe, and is required from the surface of the pipe.
What needs to be done so that the z axis reads zero from the pipe surface?

[Les Newell]

With any shape of material apart from round the height of the surface depends on the angle. This is why it uses the centre of rotation as zero.

[yurapak]

What is the algorithm for the touch sensor in this case (am I using a macros M3)?
Dim Feed
Const DRO_X = 0
Const DRO_Y = 1
Const DRO_Z = 2
Feed = FeedRate
Code "G31 Z-20 F400"
While IsMoving()
Sleep 100
Wend
Code "G92 Z0"
While IsMoving ()
Sleep 100
Wend
Code "G0 Z4 F500"
While IsMoving ()
Sleep 100
Wend
Code "F" & Feed
While IsMoving()
Sleep 100
Wend
DoSpinCW()

[Les Newell]

Why not use the referencing built into the post? It does pretty much the same thing as your M3 macro but it also takes into account the Z offset based on the tube angle.

[yurapak]

Sorry about which link you are talking about.

[Les Newell]

The PlasmaRotary Mach3 post already does the probing cycle. You don't need to add that macro.

[yurapak]

Thank you.
This means that the postprocessor already contains an algorithm for the touch sensor and the M3 macro should be left in Mach3 by default.
Or, in the postprocessor, you need to change the values of variables (refHome, or others)?

[Les Newell]

You don't want the M3 macro. In the post you will need to set refHome = false. Set switchOffset to your touch-of switch offset. To find your switch offset do this:
Put a sheet of metal on your machine and place a sheet of paper on top. Slowly jog the torch down onto the paper until the touch-off switch just operates. Zero the Z axis then pull gently on the paper and slowly jog up until the paper slides out. The Z axis position is your switch offset.

[yurapak]

Thanks for the detailed answer.